Modeling The Two-hit Hypothesis Of Schizophrenia: Combined Neonatal Stress And Postnatal Corticosterone In Rats
Funder
National Health and Medical Research Council
Funding Amount
$318,500.00
Summary
Schizophrenia is a severe mental illness defined by a number of symptoms including hallucinations, delusions, social withdrawal and cognitive impairment. Factors very early in development have been suggested to induce an increased vulnerability to this illness. Recently, it was suggested that another major event, later in life, would be needed before vulnerable individuals would develop schizophrenia. The aim of this project is to model this two-hit hypothesis in rats. We will compare the effect ....Schizophrenia is a severe mental illness defined by a number of symptoms including hallucinations, delusions, social withdrawal and cognitive impairment. Factors very early in development have been suggested to induce an increased vulnerability to this illness. Recently, it was suggested that another major event, later in life, would be needed before vulnerable individuals would develop schizophrenia. The aim of this project is to model this two-hit hypothesis in rats. We will compare the effect of various neonatal maternal separation protocols as an early stressful event, followed by chronic treatment with the stress hormone corticosterone at various stages later in life. We will also perform a detailed anatomical study of the hippocampus of these rats. This brain area has been implicated in the development of schizophrenia in humans. We will also investigate if treatment with antipsychotic drugs can prevent or reverse behavioural and neuroanatomical changes seen in the rats. This will be the first comprehensive study to model this two-hit neurodevelopment hypothesis of schizophrenia and will provide an experimental verification of a clinical concept which is very difficult to prove in patients.Read moreRead less
Advanced Paternal Age: Behavioural, Neuroanatomical And Genomic Correlates In The Offspring Of Older Fathers
Funder
National Health and Medical Research Council
Funding Amount
$501,565.00
Summary
The offspring of older fathers have an increased risk of developing disorders such as autism and schizophrenia. This is thought to be due to mutations in the developing sperm. Our group has shown in a mouse model that the offspring of older fathers have changes in brain shape and in behaviour, similar to some findings in autism. In this grant we will refine this animal model and explore the brain, behavioural and genetic correlates of advanced paternal age.
THE EFFECTS OF TRANSCRANIAL MAGNETIC STIMULATION (TMS) ON RAT MODELS OF DEPRESSION
Funder
National Health and Medical Research Council
Funding Amount
$204,274.00
Summary
Repetitive Transcranial Magnetic Stimulation (rTMS) is the direct stimulation of the brain by using high field magnetic pulses. It is a new technique that has been demonstrated to have some potential as a treatment of depressive illness and possibly other neuropsychiatric disorders. At this early stage of its investigation, the parameters of stimulation that are most likely to be therapeutic, and its mechanisms of action, are not known. Published studies vary in the frequency, duration and exten ....Repetitive Transcranial Magnetic Stimulation (rTMS) is the direct stimulation of the brain by using high field magnetic pulses. It is a new technique that has been demonstrated to have some potential as a treatment of depressive illness and possibly other neuropsychiatric disorders. At this early stage of its investigation, the parameters of stimulation that are most likely to be therapeutic, and its mechanisms of action, are not known. Published studies vary in the frequency, duration and extent of stimulation, with no firm guidelines about optimal parameters. Empirical study of the relative effects of stimulation at different frequencies, at different numbers of stimuli and for different durations is therefore important for the future development of this treatment. Such an investigation is best carried out in an animal model of depression for both ethical and practical reasons, as such studies in patients would possibly take many years and be extremely difficult to conduct. We propose such a study in rat models of depression which have demonstrated validity and utility in drug research. Rat models have a long track record in developing psychiatric treatments and are cost-effective and of proven value. We also plan to investigate the neuroanatomy of the immediate-early genes induced by TMS and compare it with electroconvulsive shock (ECS) and a tricyclic antidepressant, two established treatments of depression. The results will have implications for future human studies in guiding us toward the optimal parameters for therapeutic effects. They will also enhance our understanding of the mechanism of action of TMS in depression.Read moreRead less
Studying The Two Hit Hypothesis Of Psychiatric Illness: Role Of Brain-derived Neurotrophic Factor (BDNF)
Funder
National Health and Medical Research Council
Funding Amount
$469,553.00
Summary
Early environmental factors may play an important role in the development of psychiatric illnesses, such as schizophrenia and depression. We will study an animal model which combines early developmental stress followed by treatment with a stress hormone or chronic cannabis use in adolescence. We will assess behavioural changes and the role of a growth factor in the brain, BDNF. This wil lead to a better understanding of the role of neurodevelopmental stress in psychiatric disease.
Social Behaviour In Rats Developmentally Deficient In Vitamin D: Modelling The Negative Symptoms Of Schizophrenia
Funder
National Health and Medical Research Council
Funding Amount
$360,927.00
Summary
We are exploring low maternal vitamin D as a biological explanation for a 7-10% increase in the incidence of patients born with schizophrenia in the colder months of the year world wide. Developmental vitamin D (DVD) deficiency in rats leads to long term changes in brain development and behaviour. The aim of this research is to examine social behaviour in DVD deficient rats as a model of negative symptoms of schizophrenia and establish the neurochemical basis for this altered behaviour